someone tell me exactly what file i need to edit and where their located to mod bts.?

You'll need to be more specific. Exactly what is it you wish to mod? Also, this thread will gain more appropriate responses in the C&C Forum.

Moved to C&C Forum

I would start here: http://forums.civfanatics.com/showthread.php?t=262402

Great video on how to start out modding. :)